SparkPost API Key Tester

Test any AI or API key in your browser — instantly see if it's valid, and why it isn't. Nothing is stored.

Test your SparkPost API key with the transmissions endpoint

Data verified 2026-07-13

Key format & how to get one

1. Visit https://app.sparkpost.com/ and sign up/login 2. Go to Account > API Keys 3. Click 'Create API Key' 4. Select 'Transmissions: Read/Write' permissions 5. Copy the generated key 6. Free tier: 500 emails/month

SparkPost API docs →

Cannot test this key from your browser

This provider blocks in-browser requests or requires a server-side secret. Test it from a terminal instead:

curl -sS -X POST https://api.sparkpost.com/api/v1/transmissions -H 'Authorization: {{KEY}}' -H 'Content-Type: application/json' -d '{"options":{"sandbox":true},"content":{"from":"test@example.com","subject":"Test Email","html":"<html><body><strong>Hello</strong> world!</body></html>","text":"Hello world!"},"recipients":[{"address":"test@example.com"}]}'

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